MongoDB Articles - Page 103 of 135

You can use find() for this. Let us first create a collection with documents −> db.findInDictionaryDemo.insertOne( ...    { ...       "_id":101, ...       "AllCustomerDetails": ...       { ...          "SomeCustomerDetail1": ...          { ...             "CustomerName1":"John Doe", ...             "CustomerName2":"John Smith" ...          }, ...          "SomeCustomerDetail2": ...          { ...             "CustomerName1":"Carol Taylor", ...             "CustomerName2":"David Miller" ... Read More

You need to find the document and after that you need to use update to toggle query. Let us first create a collection with documents −> db.toggleDemo.insertOne({"CustomerName":"John Smith", "CustomerAge":28, "isMarried":true}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc7be138f9e6ff3eb0ce43b") } > db.toggleDemo.insertOne({"CustomerName":"David Miller", "CustomerAge":25, "isMarried":false}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc7be2e8f9e6ff3eb0ce43c") }Following is the query to display all documents from a collection with the help of find() method −> db.toggleDemo.find().pretty();This will produce the following output −{    "_id" : ObjectId("5cc7be138f9e6ff3eb0ce43b"),    "CustomerName" : "John Smith",    "CustomerAge" : 28,    "isMarried" : true } {    "_id" : ObjectId("5cc7be2e8f9e6ff3eb0ce43c"),    "CustomerName" : "David Miller",    "CustomerAge" : 25, ... Read More

You can use regular expression along with $not operator to ignore a specific character and display rest of them. Let us first create a collection with documents −> db.regexDemo.insertOne({"CustomerId":"Customer#1234", "CustomerName":"Chris"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc7428f8f9e6ff3eb0ce436") } > db.regexDemo.insertOne({"CustomerId":"Customer5678", "CustomerName":"Robert"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc7429e8f9e6ff3eb0ce437") } > db.regexDemo.insertOne({"CustomerId":"Customer#777", "CustomerName":"Carol"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc742ae8f9e6ff3eb0ce438") } > db.regexDemo.insertOne({"CustomerId":"Customer777", "CustomerName":"David"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc742bc8f9e6ff3eb0ce439") }Following is the query to display all documents from a collection with the help of find() method −> db.regexDemo.find().pretty();This will produce the ... Read More

To get the same result like AND in MongoDB, use the $all operator. Let us first create a collection with documents −> db.andQueryDemo.insertOne({"StudentName":"Carol Taylor", "FavouriteSubject":["C", "Java", "MongoDB", "MySQL"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc73e7a8f9e6ff3eb0ce433") } > db.andQueryDemo.insertOne({"StudentName":"David Miller", "FavouriteSubject":["C++", "Java", "MongoDB", "SQL Server"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc73ea48f9e6ff3eb0ce434") } > db.andQueryDemo.insertOne({"StudentName":"Carol Taylor", "FavouriteSubject":["Python", "PL/SQL"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc73ed38f9e6ff3eb0ce435") }Following is the query to display all documents from a collection with the help of find() method −> db.andQueryDemo.find().pretty();This will produce the following output −{    "_id" : ObjectId("5cc73e7a8f9e6ff3eb0ce433"),   ... Read More

To sum every field in a sub document, use aggregate framework. Let us first create a collection with documents −> db.sumEveryFieldDemo.insertOne( ...    { ...       "_id":101, ...       "PlayerDetails": [ ...          {"PlayerName":"John", "PlayerScore":1000}, ...          {"PlayerName":"Carol", "PlayerScore":2000}, ...          {"PlayerName":"Sam", "PlayerScore":3000} ...       ] ...    } ... ); { "acknowledged" : true,  "insertedId" : 101 }Following is the query to display all documents from a collection with the help of find() method −> db.sumEveryFieldDemo.find().pretty();This will produce the following output −{    "_id" : 101,    "PlayerDetails" : [       {          "PlayerName" : "John",   ... Read More

To check if value exists for a field in a MongoDB document, you can use find() along with $exists operator. Let us first create a collection with documents −> db.checkIfValueDemo.insertOne({"PlayerName":"John Smith", "PlayerScores":[5000, 98595858, 554343]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc6f507af8e7a4ca6b2ad98") } > db.checkIfValueDemo.insertOne({"PlayerName":"John Doe", "PlayerScores":[]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc6f512af8e7a4ca6b2ad99") } > db.checkIfValueDemo.insertOne({"PlayerName":"Carol Taylor", "PlayerScores":[7848474, 8746345353]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc6f521af8e7a4ca6b2ad9a") } > db.checkIfValueDemo.insertOne({"PlayerName":"David Miller", "PlayerScores":[]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc6f531af8e7a4ca6b2ad9b") }Following is the query to display all documents from a collection with the help ... Read More

Yes, you can set a variable collection name in MongoDB shell using JavaScript. Let us first create a collection with documents −> db.employeeInformation.insertOne({"EmployeeName":"John Smith", "EmployeeAge":24, "EmployeeSalary":450000}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc6d06baf8e7a4ca6b2ad97") }Following is the query to display all documents from a collection with the help of find() method −> db.employeeInformation.find();This will produce the following output −{ "_id" : ObjectId("5cc6d06baf8e7a4ca6b2ad97"), "EmployeeName" : "John Smith", "EmployeeAge" : 24, "EmployeeSalary" : 450000 }Here is the query to set variable collection name in MongoDB shell using JavaScript.Case 1 − Set variable with varThe query is as follows −> var status=db.employeeInformation; ... Read More

First open the CMD and then reach the BIN directory of MongoDB. The screenshot to open CMD prompt is as follows.Above we have reached the RUN dialog by pressing START and then typing RUN and ENTER.Now, type CMD and press OK button to get the command line. The screenshot is as follows −Reach the BIN directory of MongoDB. Following is how to reach the BIN −Use the query mongo –version. The screenshot of the query is as follows −Above displays that our current MongoDB version is v4.0.5.

To remove only a single document, use the remove() in MongoDB. Let us first create a collection with documents −> db.removeOnlyOneDocumentDemo.insertOne({"FirstName":"John", "LastName":"Smith"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc6ca2f9cb58ca2b005e674") } > db.removeOnlyOneDocumentDemo.insertOne({"FirstName":"Carol", "LastName":"Taylor"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc6ca399cb58ca2b005e675") } > db.removeOnlyOneDocumentDemo.insertOne({"FirstName":"David", "LastName":"Miller"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc6ca429cb58ca2b005e676") }Following is the query to display all documents from a collection with the help of find() method −> db.removeOnlyOneDocumentDemo.find().pretty();This will produce the following output −{    "_id" : ObjectId("5cc6ca2f9cb58ca2b005e674"),    "FirstName" : "John",    "LastName" : "Smith" } {    "_id" : ObjectId("5cc6ca399cb58ca2b005e675"), ... Read More

To remove key fields in MongoFB, you can use $unset operator. Let us first create a collection with documents −>db.removeKeyFieldsDemo.insertOne({"StudentFirstName":"John", "StudentLastName":"Doe", "StudentAge":23}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc6c8289cb58ca2b005e672") } >db.removeKeyFieldsDemo.insertOne({"StudentFirstName":"John", "StudentLastName":"Smith", "StudentAge":21}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc6c8359cb58ca2b005e673") }Following is the query to display all documents from a collection with the help of find() method −> db.removeKeyFieldsDemo.find().pretty();This will produce the following output −{    "_id" : ObjectId("5cc6c8289cb58ca2b005e672"),    "StudentFirstName" : "John",    "StudentLastName" : "Doe",    "StudentAge" : 23 } {    "_id" : ObjectId("5cc6c8359cb58ca2b005e673"),    "StudentFirstName" : "John",    "StudentLastName" : "Smith",   ... Read More